Removable work holders for use with automatic machine tools including a stock aligning bushing and means for locking the bushing to the feed or pusher tube are known in the art. One such arrangement embodies a circular track in the exterior surface of a stock aligning collar member of the work holder, which receives a ball therein and which includes an opposing circular track in the feed or pusher tube assembly and a set screw is provided which is adapted for urging the ball into gripping coaction with the tracks for locking the collar in selected position and in alignment with the feeding jaws of the feed tube. After a short period of time, such a set screw arrangement becomes worn and may not effectively lock the collar in selected position.
Another such arrangement for locking a work holder bushing to a feed tube is illustrated for instance in U.S. Pat. No. 1,885,224 which utilizes a collar 29 which has a noncircular bore or opening 30 therethrough for disposal in the flared bore 32 of a nut 33 threaded onto the rear inlet end of the pusher or feed tube 26. A threaded exterior sleeve 35 forces the collar 29 into wedging coaction with the flared bore 32 of a nut 33 to lock the collar 29 in a selected rotary adjusted position, thus providing for aligning the noncircular bore 30 in the collar with the jaws 11 of the chuck and the feed jaws 27 of the feed tube. The latter arrangement is unduly complex and relatively expensive to produce, resulting in increased costs and number of parts all of which tend to wear relatively rapidly and fail in extended use.